This adventure began back in about 2014 when the NLnet provided us with a grant to achieve this. Needless to say, we didn't make our original planned timelines. We had some turn over of engineers and students on the project, and Apple changed from Objective C to Swift, and we hit some early dead ends and speed humps. But we now have something that works quite nicely on iOS 12.
This port runs the core serval-dna source in a thread in the background, so that it is fully capable and fully compatible. Getting serval-dna to compile for iOS, and produce binaries that can run on all iPhone CPU types, and that could be sensibly accessed from Swift, and that would behave properly was non-trivial to say the least. We got to that point earlier in the year, and then the remaining time has been spent making a proof-of-concept app, and working through the remaining issues, like not having the thread die when the app looses focus, and working around a pile of funny little problems, including using the properly containerised paths in strange places we had overlooked it, and discovering that named sockets just don't work on the iPhone.
So today we reached the happy point of having something working, just hours before our French exchange student was due to finish up. His last great act for us was to help prepare the following short video to celebrate this milestone.
There is still some missing functionality to implement, and then the real fun begins: Trying to get the app approved for release on the Apple App Store. But that will be an adventure for another day.